ive been noticing that when i WOT at 40-45mph from overdrive it dont down shift to 2ndgear only 3rdgear. i mean at those speeds on overdrive what gear should it down shift too. cuz my rpm's at wot climb up slowly, what could this be

 

at 30-35 mine will down shift to 1st even at 70mph mine will down shift to 2nd

 

Your tunes determines at what speed the PCM will downshift you to 1/2/3. You have to be below a certain speed and exceed a certain TPS position.

If your truck isn't downshifting how you want it to(within reason), you need to tweak the tranny tables.

 

well mine at 70 it only drops to 3rd not 2nd, so then this would probably be a tuning issue

 

my truck doesnt have a tune on it just stock

 

Norm Shift MPH
1-2 36MPH
2-3 65MPH

2-1 31MPH
3-2 65MPH

Normal Shift RPM
1-2 5600RPM
2-3 5200RPM

 

Get the damn thing tuned and it'll stop this problem.